H₂O-CaCl₂ equilibrium phase diagram. Phases at equilibrium for the chemical system H₂O-CaCl₂ are shown as a function of chemical composition (mole percent CaCl₂) and temperature at 1 atmosphere pressure. There are six stoichimetric solid phases. Three of the solids, ice, antarcticite (CaCl₂^.6H₂O), and sinjarite (CaCl₂^.2H₂O), occur naturally and have mineral names. Each of the six solids melts incongruently, except for H₂O and CaCl₂. CaCl₂ melts congruently at 772°C. Peritectic and eutectic compositions and temperatures are shown on the axes. There is a chaotectic point between steam and CaCl₂^.H₂O at 178°C. Data sources for this diagram can be found in Brady (2009).
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